Leg extensions are in common use to increase a person's apparent height, or to enable a person to perform activities that would be beyond his or her reach in the absence of such devices. Leg extensions are frequently used by plasterers, dry-wall installers, electricians, and other craftsmen to facilitate working at positions above their reach, and many such devices are described in the patent literature; for example U.S. Pat. No. 7,258,652 to Florio et al, U.S. Pat. No. 6,648,803 to Jay, U.S. Pat. No. 5,498,220 to Ensmenger, U.S. Pat. No. 5,645,515 to Armstrong et al, U.S. Pat. No. 5,514,054 to Rowan, and U.S. Pat. No. 4,927,137 to Speer, all of which teach leg extensions suitable for craftsmen.
Leg extensions are also employed for amusement and physical conditioning; see for example U.S. Pat. No. 6,719,671 to Böck, and similar devices distributed by Getjumpingstilts.com LLC of Elyria, Ohio.
Leg extensions are also employed in theatrical and cinematographic applications, to enhance the apparent height of actors or to enable special effects. A particularly effective application of leg extensions may be seen in the werewolf character in the Sony/Lakeshore Entertainment film “Underworld”.
For such theatrical and cinematographic applications, the leg extension device must enable active normal-appearing walking and other motion, and be sufficiently compact to be used under costumes, and be sufficient light to enable extended use. None of the devices taught in the patents referenced above or other patents found in the patent literature, or commercially available are considered suitable for such theatrical and cinematographic applications.